The present invention relates to an applicator kit, as well as to a method of applying a substance for dental purposes. The applicator kit includes an application element having a grip area and a working end. An application member is disposed at the working end and is provided with at least one reaction substance, especially with at least one catalyst.
An applicator of this type is known from U.S. Pat. No. 5,324,128. With this applicator, an application member is accommodated in a case having holes on the side via which a fluid can enter that serves for wetting the application member.
This approach is intended to prevent the fluid from escaping if the applicator is, for example, tipped over. For this purpose, sealing surfaces are provided between the case and the application element.
Such an approach may work with cosmetic products. However, in the dental area a precise introduction of an application element is critical. Even if with U.S. Pat. No. 5,324,128 relatively small holes are provided in the case, with which a certain amount of protection is intended, this cannot preclude the fluid from accidentally penetrating and hence wetting the application element already prior to the actual process of using the same.
Numerous other applicators are also know. For example, it has been proposed to maintain an application element immersed in a liquid, and by pressing down the container for this liquid to allow a further liquid to flow in the manner of an overflow in order to prepare the mixture that is to be applied. Since this approach requires two separate sealing systems, a considerable expense is required. In addition a number of sealing bands or the like means a correspondingly great susceptibility and storage instability.
In this connection, is as furthermore known to accommodate the liquids in two chambers that are separated by a membrane that is precisely destroyed by a spike that can be activated by pressing an inner housing in. This approach, however, requires a special configuration of the spike to reliably prevent the spike from colliding with the application element.
It is furthermore known to mix reactive substances, such as a composite for tooth fillings, on a base that is coated with a peroxide, or to mix the composite with a peroxide-coated spatula. This mixing has the drawback that a homogeneous mixing is not possible since it cannot be recognized when the peroxide has been completely consumed by the relatively viscous material.
It is therefore an object of the present invention to provide an applicator kit of the aforementioned general type that is economical to produce and that enables an improved handling relative to the state of the art yet provides a good storage stability, whereby in particular a homogeneous mixing of a fluid should be possible and an ease of operation together with a saving in time should be achieved.
The applicator kit of the present invention is characterized primarily in that the application element is comprised of a deformable material, especially an elastically deformable material, wherein the application member serves for receiving the reaction substance in solid, liquid or semisolid form, with which a low viscosity fluid can be activated.
Pursuant to the present invention, the application member, in other words, for example, one end of the application element, is first provided with one or more reaction substances. For example, a double catalyst system as a salt can be applied.
The inventive application element is then immersed in a liquid, for example a dental adhesive, that accompanied by the formation of a drop surrounds the application member. The application element is then introduced into the mouth of the patient, and during the actual application process the adhesive is mixed into a cavity or upon a dentine or enamel surface with the catalyst. The catalysts that might be present in the adhesive react with the catalysts of the application member, and the entire mass hardens or sets. It is also conceivable to place only a single catalyst on the application member that, for example, increases or reduces the viscosity of the adhesive.
It is particularly expedient pursuant to the present invention that the application of the adhesive to the application surface particularly promotes even obviously chemical reactions. Due to the distribution of the adhesive, even the salt present on the application member as reaction substance is well released, so that the self hardening process is enhanced. In this connection, pursuant to the present invention it is particularly expedient that the applicator kit eliminates the necessity for light hardening of the applied adhesive. Thus an entire process step, for example during introduction of an inlay or during fastening of a crown, is eliminated.
Pursuant to the present invention, the application element comprises a deformable material. In this context, xe2x80x9cdeformablexe2x80x9d means a material hardness that is suitable for the application.
Thus, for example, the applicator can comprise a polymeric material, with the application member extending essentially in the form of a small rod to a working end. At this end, the inventive application member is provided, which is either monolithic, in other words comprises the same material as the rest of the application element, or is comprised of some other material. For example, the material for the application member can be a textile, brush hairs, a sponge, fibers, polymeric material, hard or laminated paper, or wood, with the configuration of a micro-brush being preferred. In addition, it is preferable that the material of the application member be significantly softer than dentine and tooth enamel in order during application not to have to worry about any damage to the tooth.
Pursuant to the present invention it is particularly important to have the viscosity of the liquid or fluid in the range of 10 to 500,000 mPa, especially 1,000 to 100,000 mPa, and preferably 10,000 to 50,000 mPa. The low viscosity ensures that the reaction substance will be released entirely to the application member, as has shown to be the case in tests conducted with an inventive applicator kit. The small brush hairs of a micro-brush used pursuant to one advantageous specific embodiment of the present invention evidently produce capillary effects so that with an appropriate viscosity the liquid creeps along the hairs and can directly release the reaction substance. In addition, as a liquid adhesive it enables a laminar spreading on the application surface, to which contributes the very low surface tension of the liquid.
Pursuant to the present invention, it is particularly expedient that the application member itself be provided with the reaction substance that can be activated by the liquid. The reaction can be activated by pushing in a housing that contains the fluid, or by immersion into an otherwise suitable container.
If a housing is used, it is merely necessary to provide a circumferential sealing of the sealing mechanism in order to maintain storage stability. The inventive application member is preferably provided with one or more catalysts. For this purpose, it is immersed into a benzene sulfinic acid solution and/or into an amine solution, for example diethanol-p-toluidine, and allowed to dry. The reaction substance is stored as a dry substance and is hence particularly stable. Therefore, as a reaction substance a double coating by two catalysts can also be applied, so that with the activation upon introduction of the sealing mechanism and overcoming of the sealing function by the fluid, in practice three components are brought together and react appropriately, whereby the fluid is used as adhesive for the adhesion of composite materials upon tooth enamel or dentine.
In this embodiment, the inventive applicator kit can be made available as a single-dose unit. However, in other embodiments it is also possible to separately prefabricate and package the application member, for example as an individual brush or brush comb, and to immerse it into the fluid for use. The single-dose unit or the individual or multiple brush (brush comb) can preferably be sealed in foil, for example of aluminum, or coated plastic, in order to improve the storage stability. If, for example, larger cracks are to be sealed or tooth enamel is to be applied, an adequate quantity of material can be made available in this manner.
It is particularly expedient pursuant to the present invention if the reaction substance is present in solid form. However, this is by no means absolutely necessary, since it is also possible to provide the material in semisolid or even liquid form as drops. Depending upon the type of fluid, not only a light hardening but also a self hardening adhesive can be made available.
It is particularly advantageous pursuant to the present invention to provide quite wide slots for the supply of the fluid to the application member. When the application element, in other words the seal, is strongly pushed into the housing, the fluid is pressed upwardly, accompanied by pronounced swirling, through the gap between the base of the sealing mechanism and the inner side of the housing, and flows at a quite high flow velocity into the region provided with micro hairs. As a consequence, an intensive mixing results, so that the chemical reaction is very rapidly initiated by the catalysts, and the finished adhesive is immediately ready for use. The required reaction time can, for example, be one second; the time does not generally fall below such a short time span.
To this extent, with surprisingly simple measures an applicator kit is made available that on the one hand is stable for a long time and on the other hand is rapidly usable.
Pursuant to one particularly advantageous specific embodiment to the present invention, even the sealing mechanism can be pressed down with the application element. This can be realized either with the blunt tip of the application member, or with an appropriate projection of the shaft of the application element.
It is furthermore particularly advantageous pursuant to the present invention if the application member is embodied as a micro-brush. Such a micro-brush can be produced by flocking the tip of the shaft of the application element. Within the context of the present invention, the application member means any type of application mechanism produced by applying an absorptive substance onto the shaft tip, so that even a foam type of structure could be provided.
The absorptive capacity of the micro-brush for the fluid can be adapted to the desired application volume in conformity with the hair length, in other words the type of flocking, or by other suitable measures, for example, to wet larger tooth surfaces, which correspondingly require more adhesive agent, it can be expedient to provide a micro-brush having a greater drop receiving capacity for the fluid, with the brush hairs extending to the side supports of the sealing mechanism.
Pursuant to another particularly expedient embodiment of the present invention, such an applicator can be bendable in a particularly advantageous manner. For this purpose, a constriction or narrowed portion can be provided about the shaft of the application element to permit a plastic deformation of the application element such that it can be bent after removal from the housing.
This bending can, in a particularly expedient manner, be effected in such a way that the application element is first withdrawn by a few millimeters from the housing and is then bent. In this state, the micro-brush is still protected by the housing so that no separate additional bending tool is needed. Pursuant to another particularly advantageous specific embodiment of the present invention, the constriction can be disposed just below a widened or thickened portion, the front abutment shoulder of which at the same time serves for introduction of the sealing mechanism. The widened portion then at the same time forms the transition between the grip and the shaft, and offers to the dentist an ergonomically favorable handling reliability that prevents him from inadvertently contacting the tip region of the application element that carries the reaction substance while he guides the application element.
Pursuant to a further advantageous specific embodiment, the grip, which is adjacent to the widened portion, can be provided with grooves or other suitable surface configurations that provide a favorable grip.
The inventive applicator kit can be produced decidedly economically as a single-dose unit, with the micro-brush preferably being made of polypropylene.
The inventive sealing mechanism fulfills a number of functions in a particularly expedient manner. On one hand, the base of the sealing mechanism, prior to use of the applicator, reliably seals against an inner annular bead of a housing. It is preferably made of a polymeric material that is somewhat softer than the material of the housing. At the same time, it serves for guiding the shaft of the application element, in which connection it is preferred that the friction between the shaft and the sealing mechanism on the one hand, and between the sealing mechanism and the housing on the other hand, also be great enough in the region of the upper overflow ring that the components of the inventive applicator kit do not inadvertently fall apart.
It is to be understood that prior to use the inventive applicator is accommodated in a suitable, preferably air tight, package so that also the reaction substance is not subjected to any environmental influences through the narrow gap, the ring of the sealing mechanism, and the shaft.
Further specific features of the present invention will be described in detail subsequently.